The objective is to study the role of specific humoral immunity to pigmented cells in the pathogenesis of vitiligo. It is planned to initially determine whether there is an increased incidence of antibodies in persons with vitiligo. This will be done by measuring antibodies to melanocytes by in vitro complement-fixation in persons with simple vitiligo and vitiligo associated with autoimmune diseases, mucocutaneous candidiasis, or melanoma and comparing their incidence to that in persons with unrelated dermatosis and normal individuals. Antibodies to pigmented cells will also be measured by a radioisotopic antigen binding assay that is not influenced by the complement fixing ability of the antibody. The specificity of antibodies to melanocytes will be examined by testing their reactivity to a variety of unrelated normal and malignant human tissues. If antibodies to pigmented cells are found to be increased in vitiligo, or in subsets of the disease, their role in pathogenesis will be investigated by: a) correlating their presence to the stage, extent, and activity of the disease, b) studying their ability to damage pigmented cells in vitro, and c) studying, by direct immunofluorescence, whether there are abnormal deposits of immunoglobulin and/or complement over melanocytes in lesions of vitiligo. Hopefully, the results of these studies will indicate whether abnormalities in the humoral immune response to pigmented cells occur in vitiligo, and if so, suggest whether they play a role in the pathogenesis of the disease.